The objective of the present study was to assess relations between depression and personality disorders, and to examine how psychiatric problems are linked to maternal caretaking behavior. Subjects were affectively ill and well mothers and their children from 89 families participating in a longitudinal study of child development and childrearing. Psychiatric and behavioral measures were obtained at three time periods: when the child was a toddler, early school age, and preadolescent. A personality disorder assessment of the mother was made at the third time period. Affectively ill mothers reported more personality disorder symptoms than did well mothers. Severity of affective illness and recency of episodes were related to higher rates of personality disorder symptoms. The behavior of affectively ill mothers in interaction with their children was related to mothers' personality disorder symptoms. For example, unipolar mothers reporting higher rates of symptoms in the paranoid, schizoid, or schizotypal disorder categories (categories that are particularly indicative of interpersonal impairments) were less engaged and involved in interaction with their children. On the other hand, bipolar mothers' high level of engagement was related to higher rates of symptoms in the dependent and borderline personality disorder categories. Results demonstrate the importance of considering multiple sources of psychiatric impairment in assessing potential risks to the parent-child relationship.